Flushing cisterns

Abstract

A flushing cistern to produce an energetic flush with a reduce volume of water, some 5 or 6 liters for low-level use. The cistern has a housing supporting a rotatable water holder having a large flow aperture in a curved surface and otherwise closely conforming to the inside of the housing. The flush outlet is a large tapering outlet of hydraulically-efficient form to which the aperture matches when the holder is rotated to produce a flush. The filling of the water holder can be arranged to occur only when the holder is in the correct position. Fault conditions are indicated by a warning flow of water from an overflow or elsewhere.

We claim: 
     
       1. A flushing cistern comprising: a cistern body having a water outlet in the bottom thereof;   a water holder mounted for rotation in said body and having an aperture in the periphery thereof, said holder being rotatable between a first water receiving position wherein said aperture is uppermost and a second water dumping position wherein said aperture is lowermost, said aperture and the entrance to said outlet generally matching in configuration and the portion of the peripheral wall of said holder extending from said aperture in the direction of rotation from said first position to said entrance and the portion of the wall of said body transversed by said aperture during rotation from a position where water can start to flow from said aperture to said second position being substantially conformed to and closely spaced from each other, whereby said body portion obstructs said aperture during rotation from said first to said second position to substantially retain most of the water in said holder until said second position is reached;   means to supply water to said holder in said first position; and   manually operable means to rotate said holder from said first to said second position.   
     
     
       2. A cistern according to claim 1 including means to vent air from the water holder in the second position to ensure free dumping. 
     
     
       3. A cistern according to claim 1 including means to limit the speed of rotation of the water holder. 
     
     
       4. A cistern according to claim 1 having a holder water charge of no more than 6 liters and providing a substantially even flushing water flow discharged in less than 2.5 seconds. 
     
     
       5. A cistern according to claim 1 having a holder water charge of no more than 6 liters and providing a sustained average flushing water flow in excess of 1.9 liters per second. 
     
     
       6. A cistern according to claim 1 including a dash-pot to control the return of the water holder to the first position after dumping. 
     
     
       7. The cistern defined in claim 1 wherein the outlet tapers from the entrance to a reduced exit. 
     
     
       8. The cistern defined in claim 1 in which the holder includes bias means for urging said holder to rotate from the second position to the first position. 
     
     
       9. A cistern according to claim 8 in which bias means includes at least one pocket to retain water in the second position and having a vent hole to control flow of retained water from the pocket. 
     
     
       10. The cistern defined in claim 1 in which the holder includes bias means for retaining said holder in the second position until empty. 
     
     
       11. The cistern defined in claim 10 in which the bias means includes a pocket to retain water in said second position and having a vent hole to control flow of retained water from said pocket. 
     
     
       12. The cistern defined in claim 1 in which ther water supply means includes chute means attached to the holder to direct water into said holder only in the first position. 
     
     
       13. The cistern defined in claim 1 in which the water supply means includes automatic means for starting the flow of water in said first position and stopping the flow when the water in the holder reaches a predetermined level. 
     
     
       14. The cistern defined in claim 13 including means for receiving an overflow of water from the holder in the event of failure of the automatic means to stop the flow, and visible drain means for said overflow receiving means to indicate such failure. 
     
     
       15. The cistern defined in claim 13 including means for receiving water from the water supply means in the event of failure of the automatic means and starting the flow in other than the first position, and visible drain means for said receiving means to indicate such failure. 
     
     
       16. A flushing apparatus comprising: a cistern body having a water outlet in the bottom thereof;   a water holder in said body having an aperture and mounted for movement between a first water receiving position where said aperture is uppermost and a second water dumping position where said aperture is lowermost;   means to supply water to said holder, including deflector means movable with said holder to receive and direct water into said holder only in said first position; and   means for receiving and directing the water from said supply means to a visible fault-indicating outlet in the event of water flow from said supply means in other than said first position.   
     
     
       17. A flushing apparatus comprising: a cistern body having a water outlet in the bottom thereof;   a water holder in said body having an aperture and mounted for movement between a first water receiving position where said aperture is uppermost and a second water dumping position where said aperture is lowermost;   means to supply water to said holder, including automatic means for starting the flow into said holder in said first position and stopping the flow when the water in said holder reaches a predetermined level; and   means for receiving and directing to a visible outlet overflow of water from said holder to indicate failure of said automatic means to stop the flow.